"superficial head: recurrent branch of median nerve (C5 - T1)"
"deep head: deep branch of ulnar nerve (C8 - T1)"
"origin:"
"insertion: proximal phalanx of the thumb"
"action: flexes thumb at metacarpophalangeal joint"
"arterial supply: superficial palmar arch"
"arterial supply: superficial palmar arch"
"innervation:"
Expected headings
"Summary"